1. Technical Field
The present invention relates to a printing control device for printing, on a printing medium, a color image layer representing an image and a background image layer which is superimposed onto the color image layer.
2. Related Art
A known example of this type of printing control device is a device in which nozzles for discharging ink are divided into a plurality of nozzle groups and ink is discharged from each nozzle group as a printing medium moves (as described in WO 2005/105452). Specifically, in this device, printing is carried out by using nozzles including a row of nozzles which discharge color ink for recording a color image and a row of nozzles which discharge special ink for recording a background image and by moving the nozzles in a main scanning direction with respect to the printing medium, and also by discharging ink from the nozzles onto the printing medium while moving the printing medium in a sub-scanning direction with respect to the nozzles. Furthermore, the nozzles are divided into a first nozzle group which is arranged at an upstream side where printing is first carried out and a second nozzle group which is arranged at a downstream side and being adjacent to the first nozzle group, and ink is discharged from the nozzle rows of each nozzle group when the printing medium is moved in the sub-scanning direction with respect to the nozzles. For example, special ink is discharged from the nozzle rows of the first nozzle group to form a background image, and after a recording medium on which the background image has been formed is transported in the sub-scanning direction, color ink for forming a color image layer is discharged from the nozzle rows of the second nozzle group in the portion in which the background image is formed. Printed material in which a color image layer is formed on a background image layer on a printing medium, can thus be obtained.
However, with this kind of printed material, when printing is carried out by arranging the background image layer and color image layer on top of each other, there are problems in that specific colors are not distinct and there is an increase in the amount of ink because the characteristics of the color ink in each layer are not taken into account.